One hundred five elderly Japanese who had trouble swallowing were randomly divided into three groups. One group was exposed to black pepper oil (BPO), one to lavender, and one to distilled water. There was a significant increase in the speed of swallowing reflex, concentration of serum substance P, and number of swallows per minute for the group exposed to BPO but not for the other groups. Brain scans were taken for ten individuals in the black pepper oil group before and after treatment. Inhalation of BPO apparently also activates two regions of the brain. Since difficultly in swallowing is linked to difficultly in breathing, the authors argue that exposure to BPO may help prevent pneumonia in the elderly.

Suggested Lesson Structure:

Answer questions about and discuss the two articles

Activity: Design This Experiment

Discussion Points:

Have the students answer these questions in groups of 3 or 4. They are expected to have already read the articles before coming to class:

What is the motivation for studying the effect black pepper scent on swallowing reflex?

What was the design of the experiment, in general terms?

How many subjects were in the experiment?

What is good evidence that they were randomly assigned to the three groups?

What different measurements were taken and why do you think they looked at so many?

What were the controls and why do you think they were chosen?

Why were the brainscans done and what do they show?

Was the main hypothesis proved in this experiment?

Active Learning Modules:

Design This Experiment

Divide students into groups of 3 or 4.

Give each group an hypothesis and tell them to design a reasonable experiment to test it.